Heating flame regulation



Feb. 18, 1947.

l'hoio Cell E. W. DECK HEATING FLAME REGULATION Flled June 12,

AMPLI HER REACTOR ATTO RN EY Patented Feb. 18, 1947 HEATING FLAMEREGULATION Elbe W. Deck, Plainfleld, N. 1., alslgnor to Union Carbideand Carbon Corporation, a corporation of New York Application June 12,1942, Serial No. 446,810

24 Claims.

This invention relates to the regulation of desired characteristics orheating flames, particularly flames produced by the combustion of amixture of fuel gas and oxidizing gas, such as oxygen and acetylene, andused in seam weldin operations or stationary welding operations, such asbronze welding and pressure welding, wherein the metal is brought up tothe desired temperature quickly and then held at substantially thattemperature for a heat soaking period. This invention also relates toapparatus for effecting such regulation. This invention particularlyrclates to the regulation of such flames wherein desiredcharacteristics-as the flame temperature, available heat, velocity ofthe flame Jet, and rate of flame propagation. all of which aifect theheating eflect of the flame or rate of transfer of heat from the flameto a workpiece-are varied. Other characteristics-as the relative lengthof the inner cone, distance between the end of the inner cone and thesurface of the work or contact area of the inner cone, and the ratiobetween oxygen and fuel gas in the combustible mixture (which afl'ectsthe chemical activity between the flame and the material beingheatedi-are maintained substantially constant.

The amount of heat transferred, or B. t. u. absorbed by the workpiece,is dependent on the total available B. t. u. and the efliciency of heattransfer. The total available 13. t. u. may be altered by varying thequantity or type of constituents of the flame. The efliciency of heattransfer may be altered by varying the temperature of the flame, thevelocity of the flame Jet, and the rate of flame propagation. Tomaintain the maximum effectiveness of the heating operation, it isdesirable that the spacing between the blowpipe and the surface of theworkpiece shall be maintained substantially constant. that the length ofthe inner cone of the flame shall be maintained substantially constant,that the character of the flame, i. e., neutral, oxidizing, orcarburizing shall be maintained substantially constant or varied only asnecessary, and, in some instances, that a blowpipe or equivalent flameproducing means shall be moved across a workpiece at a substan. tiallyconstant speed. Thus, an object of this invention is to provide a novelmethod oi and apparatus for heating flame regulation. whereby theheating eflect of the flame, or the amount of heat transferred to theworkpiece, may be varied as desired without substantially impairing theeffectiveness, or facility with which the heating operatlon can becarried out, i. e., without changing the length of the inner cone or theseparation of 2 the blow-pipe and the work or the rate of relativetravel of the work.

Among other objects of this invention are to provide a novel method ofcontrolling the rate of heat transfer from a flame to a workpiece; toprovide a novel method of varying the temperature or other desiredcharacteristics of a heating flame without varying the length of theinner cone of the flame, and without altering a desired carburizing oroxidizing effect of the flame, or without altering the chemicalcharacter of the flame from neutral, when the same is to be maintained;to provide such a method wherein the tendency for flashbacks isminimized; to provide such a method by which a surface area may beheated relatively quickly to a desired temperature and that temperaturemaintained without the danger of overheating the surface of the work; toprovide apparatus for carrying out the above method; and to provide suchapparatus which may be made substantially automatic in operation, andalso may be made to respond to variations in heating conditions at thesurface of the workpiece. Other objects and novel features of thisinvention will become apparent from the followin r ption andaccompanying drawing, in which:

Fig. 1 is a schematic illustration, partly in section, of ancity-acetylene blowpipe, and apparatus constructed in accordance withthis invention, for regulating the flame produced by the blowpipe;

Fig. 2 is a cross-section of an oxygen-air-seetylene regulator andproportioner constructed in accordance with this invention; and

Fig. 3 is a. schematic illustration of constant speed strip weldingapparatus, including a multiflame oxv-acetylene blowpipe, and apparatusby which the flames produced by the blowpipe are regulated in accordancewith the method of this invention.

In accordance with the method of this invention, in order to vary theheating eflect of a flame, the combustible mixture formin the flamewhichcombustible mixture is normally formed by mixing fuel gas and anoxidizing gas having a relatively high oxygen content, preferablysubstantially pure oxygen-is instead formed by mixing fuel gas and anoxidizing gas mixture consisting of oxygen and oxidizing gas having arelatively low oxygen content, preferably air. The relative proportionof oxygen to air (oxygen to nitrogen) in the oxidizing gas mixture isincreased when a greater heating eflect is desired. At the same time.the pressure and flow of the oxidizing gas mixture is increasedproportionally. and the pressure and flow of the fuel gas is varied inaccordance with the variation in oxidizing gas pressure and flow.

Also in accordance with this invention, fuel gases such as acetylene andhydrogen may be mixed with oxygen, and the pressure and flow ofacetylene regulated to vary the heating effect of the flame. thepressure and flow of oxygen bein regulated in accordance with that ofthe sect?- lene. It will be evident that other fuel gases. or mixturesthereof, may be utilized, in carrying out this invention.

By the above method, the heating eifect of the flame may be varied asdesired, since the available heat and the temperature of the flame willvary in accordance with the relative proportion of oxygen in theoxidizing gas or in accordance with the relative amount of acetylene inthe fuel gas mixture. and the velocity of the flame Jet will vary inaccordance with the pressure of fuel gas and oxidizing gas. Not onlywill the length of the inner cone remain substantially constant, butalso the chemical character of the flame will remain unchanged. Thelatter feature is particularly important when the nature of the workrequires a constant character of flame, such as carburizing for certaintypes of welding, oxidizing for rapid heating, or neutral for otherheatin operations.

Apparatus for carrying out the above method and constructed inaccordance with this invention, as illustrated in Fig. 1, may comprise aproportioner P for controlling the relative proportions of oxygen andair in an oxidizing gas mixture formed in a regulator R. Regulator Rcontrols the pressure or amount of fuel gas or acetylene passing to ablowpipe B, along with the airoxygen mixture. Regulating valves V onblowpipe 3 are adjusted to provide the desired initial mixture of oxygenand acetylene, or oxidizing gas and fuel gas, passing to a tip T. Theinitial setting of valves V is preferably maintained, since variationsin temperature and heating effect of the flame are readily achieved byadjustment of proportioner P. Regulator R and proportioner P may becombined in a single casing. as in Fig. 2. in which a combinedproportioner and regulator RP is illustrated.

The strip welding apparatus illustrated in Fig. 3 comprises, in general,a machine welding blowpipe M provided with a head H adapted to di rect aplurality of high temperature heatin flames along a welding seam on aworkpiece W. The relative proportions of oxygen, acetylene, and air inthe combustible mixture, forming the heating flames discharged from headH, are determined by a combined regulator and proportioner RP, which iscontrolled by a solenoid S. In turn, solenoid S is controlled by aphoto-cell control unit C, which is responsive to variations in athermal condition of the welding seam.

The above apparatus may also be utilized in carryi g out the method ofthis invention wherein the proportions of a fuel gas mixture are varied.and the pressure of oxygen is varied in accordance with the pressure ofa. fuel gas such as acetylene, as explained previously. Thus, theproportioner P of Fig. 1 may control the relative proportions ofacetylene and hydrogen, for instance, while the regulator B may controlthe pressure and flow of oxygen in accordance with the pressure and flowof acetylene. Similarly, the combined proportioner and regulator of Fig.2 may be supplied with acetylene, hydrogen, and

oxygen; and the regulator and proportioner RP of Fig. 3 may control therelative proportions of acetylene, hydrogen, and oxygen, to weldingblowpipe M. Thus, it will be understood that oxygen and air may bereplaced by acetylene and hydrogen or the like. respectively, and thatacetylene or fuel gas may be replaced by oxygen, in the variouspassages, chambers, hoses, etc.. of the apparatus described below.

Referring again to Fig. 1, for a more detailed description of theapparatus illustrated therein. oxygen and air are supplied through hosesII and II, respectively, to casing l2 of the proportioner P; The oxygenflows from an inlet chamber ll to an outlet chamber 14, such flow beingcontrolled by a valve II, Valve II is controlled by a. diaphragm l8,actuated by a compression spring l1 and the differential between thepressure in oxygen outlet chamber l4 and the pressure in an air inletchamber ll. oxy en pressure being exerted against the valve side of thediaphragm and air pressure being exerted against the opposite side ofthe diaphragm. The force exerted by spring I1 is adjusted by a screw l8,which may be turned down to cause spring II to exert a greater forceagainst diaphragm ii and thereby produce a higher oxygen pressure inchamber l4. This produces a correspondingly increased flow of oxygenthrough hose 2|, from chamber l4 to oxygen inlet chamber 22 of regulatorR. The air pressure is normally maintained substantially constant,though, if desired, an increase or decrease in the oxygen pressure canbe produced by increasing or decreasing the air pressure, due to theeffect upon diaphragm is and consequent opening or closing of valve It.

The air is led from chamber II through a hose 23 to an air-oxygen mixingchamber 24 of regulator R. Oxygen from hose 2| passes into oxygen inletchamber 22 and flows through a restricting orifice 25 into mixingchamber 24. From chamber 24, the oxidizing gas or air-oxygen mixtureflows through a hose 26 to blowpipe B,

When the oxygen pressure in chamber l4 increases as regulated by screwIt. the oxygen pressure in chamber 22 of regulator R increases, and flowthrough orifice 25 proportionally increases. The resultant increasedflow of oxygen into chamber 24 causes the relative amount of oxygentherein to increase, and the proportion (and partial pressure) of oxygenin the air-oxygen mixture to increase. As the oxygen pressure (and theflow of oxygen through the orifice 25) increases the pressure differencebetween the air supply line H and the chamber 24 decreases, reducing theflow of the air. so that a point will be reached at which very littleair will be present in the chamber 24, and substantially pure oxygenwill be delivered through hose 28 to blowpipe B. When this point isreached, oxygen will back up through hose 2! into chamber it. As long asthe oxygen pressure for passage 2| is well above the air pressure inpassage 28, there will be no danger of the air pressure in the mixingchamber 24 stepping the flow of oxygen because there will still be anoxygen pressure drop across the orifice 2!. This will also be the casewhen no air is supplied, as when the heating flame of blowpipe B isbeing adjusted to the desired oxy-acetylene or oxyfuel gas ratio byvalves V at the beginning of the heating operation.

The pressure of fuel gas or acetylene flowing to the blowpipe-from aninlet hose 28 through an inlet chamber 28 in regulator R, to an outletchamber II and through a hose II to blowpipe B-ls regulated inaccordance with the pressure 01' oxygen in chamber 22. The reason thegas from the hose 28 is regulated in accordance with oxygen pressure isbecause in practice the fuel gas usually passes through a pressureregulator so that the fuel gas pressure is fairly constant in the supplyline 28. For this purpose, a valve 32, which at all times automaticallycontrols the flow of acetylene from chamber 2! to chamber II, isattached to and actuated by a double diaphragm arrangement, comprisingan upper diaphragm l3 and a lower diaphragm II, the two diaphragms beingconnected together to move in unison, The force produced by the pressureoxygen in chamber 22, exerted against diaphragm 38 which forms the lowerwall of chamber 22, acts to open valve 32, while the force produced bythe pressure of acetylene in chamber ll, exerted against diaphragm IIwhich forms the upper wall of chamber ll. acts to close valve 32. Thus,the pressure and flow of acetylene is determined by the pressure andflow oi ongen, which in turn determines the pressure and flow ofoxidizing gas and the proportion of oxygen in the oxidizing gas mixture.

The double diaphragm arrangement is a safety feature which assists inpreventing the formation of a combustible or explosive mixture in eitherthe oxygen or acetylene supp y line, due to leakage from the other line.Vent 35 in casing 36 of the regulator provides communication between theatmosphere and the space between the diaphragms, so that ii eitherdiaphragm is ruptured, the fuel gas or oxygen, as the case may be, willescape to the atmosphere. It will be understood that the eflective areasof the two diaphragms may be difl'erent, so that a change in the oxygenpressure in chamber 22 will produce a fractional proportional change inthe acetylene pressure in chamber 80.

The acetylene or fuel gas and oxidizing gas mixture are mixed in theblowpipe B to form a combustible mixture, which is discharged from tip Tto produce a heating flame. Changes in temperature and heating effect ofthis flame are readily effected. Assuming that screw I! is set for thelowest flame temperature obtainable with the setting of valves V, and itis desired to increase the heating effect of the flame, the screw II ismerely turned down so that spring I! will exert a greater force againstdiaphragm l8. This causes valve II to open to a greater extent, causesthe pressure of oxygen in chamber II to increase, and also causes agreater amount of oxygen to flow to regulator R and the pressure inchamber 22 to increase. This results in a greater flow of oxygen throughorifice 2!, a displacement of air in chamber 2|, an increase in theproportion of oxygen in the oxidizing gas mixture, and an increase inthe pressure of the oxidizing gas mixture. At the same time, theincrease in the pressure of oxygen in chamber 22 causes an increase inthe pressure and flow oi acetylene, with a resultant increase in thetotal amount of omen and acetylene in the combustible mixture. Theresultant increased rate oi flame propagation is compensated by theincreased velocity 0 the jet, due to the increased pressure of oxidizinggas and fuel gas. However, the ratio of oxygen to acetylene in thecombustible mixture remains the same, and neither the character '01 theflame nor the length of the inner cone of the flame will be changed.Thus, the heating eflect and temperature of the flame may be varied overa wide range while maintaining the eflectiveness or the heat- 6 ingoperation. It is estimated that, by this invention, the temperature of asubstantially neutral oxyacetylene heating flame can be varied over arange extending from approximately 4000 F. to 5500 1''.

Similarly, when the heating eii'ect oi the timeisregulatedbyvaryingtheconstimentsoiatuel gas mixture, acetylene may besupplied through hose ll, hydrogen or the like through hose II, and menthrough hose 2|. Turning down screw ll will cause the pressure ofacetylene to increase, the relative proportion of acetylene in the fuelgas mixture to increase, and the pressure and flow of oxygen toincrease. Thus, the heating eflect oi the flame may be increased withoutchanging substantially the character of the flame or length of the innercone.

The combined regulator and proportioner RP illustrated in Fig. 2.comprises a casing II to which an ongen inlet pipe II is connected; anupper cap II, to which an air inlet pipe I! is connected; and a doublelower cap, consisting oi an intermediate section 48 and a lower sectionII, to which an acetylene inlet pipe II is connected. Oxygen 'i;;' frompipe ll through an inlet passage 40 to a valve chamber 41, formed incasing IS. The flow of oxygen from valve chamber 41 to an oxygen chamber48 is controlled by a valve 49, which seats against the taperedunderside oi an oriflce id in a valve bushing II. The stem of valve Illextends through oriflce 50, while bushing ll threadedly engages casing30, to close the upper end oi valve chamber 41 and hold a sealing gasketit against a suitable shoulder in the casing. The upper end or the stemof valve is is attached to a diaphragm 53, the periphery of which isclamped securely between casing II and cap Ii for sealing purposes. Thecentral portion of diaphragm 93 is clamped between a pair of bearingplates 54, attached to the stem of valve 49 and provided with upturnededges to prevent rupture oi the diaphragm upon flexing. Diaphragm illmay comprise a rubber disc, as shown. or may comprise several layers ofrubber or other suitable material, such as metal, synthetic rubbersubstitute. or canvas impregnated with rubber or the equivalent.Diaphragm It forms a partition between oxygen chamber 48 and anair-oxygen mixing chamber 56, formed principally in cap ll, oxygenpassing from chamber It to mixing chamber ii through an oriflce S8 inthe diaphragm. Air passes into chamber II from inlet 42, the mixture ofair and omen being led from chamber 55 by an outlet pipe 51, to ablowpipe or similar apparatus.

The pressure of oxygen in chamber 48 and the consequent flow of oxygenthrough oriflce which in turn determines the proportion of oxygen to airin the oxidizing gas mixture, as explained in connection with orifice 25of the apparatus of Fig. l-is determined by the force exerted by arelatively heavy coil spring I! disposed in chamber 55 and bearing atits lower end against the upper diaphr zm plate M. The force exerted byspring 58 may be adjusted by a screw 58, extending through cap II andengaging a bearing disc 6| interposed between screw 5! and spring Bl.Screw 59 is provided with a packing gland 6| to prevent leakage fromchamber I. The force exerted by spring 58 is opposed. in part, by a coilspring I! which bears at its lower end against a suitable recess inbushing i0 and :51: its upper end against lower diaphragm plate Thepressure and flow of acetylene, as before,

are proportional to the pressure and flow 01' oxygen. The flow ofacetylene from inlet II to an outlet pipe Gl-through an inlet passage IIand a valve chamber 86 to a diaphragm chamber 81 and an outlet passage68-is controlled by a valve 89, in turn connected to a double diaphragmassembly including a diaphragm 10. Oxygen pressure is exerted againstdiaphragm 10 in a chamber ll, formed between housing 38 and thediaph'ragm, the periphery of which is clamped between housing andintermediate cap II, for sealing purposes. Oxygen is led from chamber 48to chamber II by a connecting passage 12, so that variations of oxygenpressure in chamber II will be communicated to chamber H, and thepressure exerted against diaphragm ID will cause the flow oi acetyleneto be correspondingly regulated. Acetylene valve 89 is similar to oxygenvalve 49, seating against the tapered lower portion of an orifice I3 ina bushing 14 which threadedly engages lower cap 44 and clamps a gasket15 against a shoulder formed in the cap, for sealing purposes.

Utilized principally for safety purposes, the double diaphragmarrangement includes a lower acetylene diaphragm 16, while a chamber 11,formed in intermediate cap 43 between upper oxygen diaphragm Ill andlower acetylene diaphragm 16, is vented to the atmosphere by holes 19extending through cap I. Should rupture of either diaphragm occur, theoxygen or acetylene, as the case may be, will be vented to theatmosphere through holes 19, instead of passing into the other line. Asbefore, the possibility of a combustible or explosive mixture beingformed in either supply line is avoided.

The upper end of chamber 81 is closed by diaphragm 16, which is clampedbetween intermediate cap I! and lower cap 44. The central portions ofdiaphragms l and 18, are clamped between pairs of discs 80 and 8|,respectively. The upper end of the stem of valve 89 is attached todiaphragm l6 and dies Bl, while diaphragms l0 and I6 are securedtogether, to move in'unlson, by a stud 82. Also, the lower end of aspring 83 extends into a recess in bushing 14 while the upper end of thespring engages lower disc III at diaphragm 15.

Spring 83 compensates in part for the higher pressure at which oxygennormally is passed through the device, and for the diflerence in areabetween diaphragms and 16, which difference in area is such that achange in oxygen pressure will produce a proportional but unequal changein the acetylene pressure. If desired, the area of diaphragm 16 may bemade equal to or greater than the area of diaphragm ll. Also, a springmay be provided to bear against the lower end of valve 69, so that anydesired relation between the oxygen pressure and the acetylene pressuremay be obtained. The relative areas of diaphragm Ill and I6 and thestrength of spring 83 may be varied as desired, particularly for is thesame. Also, when acetylene, hydrogen or the like, and oxygen aresupplied through pipes 40, I2, and II, respectively, the operation ofthe apparatus again corresponds to the operation of the apparatus ofFig. 1 when corresponding gases are utilized.

In the constant speed strip' welding apparatus illustrated in Fig. 3,the combined proportioner and regulator RP is similar in construction tothe combined proportioner and regulator RP of Fig. 2. Thus, oxygen, air,and acetylene are supplied thereto by hoses 85, 86, an 81, respectively.Acetylene flows to the blowpipe M through a, hose 88, while theoxidizing gas mixture of oxygen and air flows to blowpipe M through ahose B9. During the welding operation, the head H and control unit C aremoved at a substantially constant speed along the seam to be welded, orthe work W is moved between the two at a substantially constant speed.The spacing of the head above the work and the control unit below thework are maintained substantially constant. The operation of thecombined proportioner and regulator RP is controlled by solenoid S, thecore of which is operatlvely connected with a spring, similar to spring58 of the regulator and proportioner RP of Fig. 2. The amount of currentpassing through the solenoid S determines the pull exerted upon thecore, which in turn determines the pressure of the spring and therebycauses the proportions of oxygen and air in the oxidizing gas mixtureand the pressure of acetylene to vary as desired. As solenoid S iscontrolled by a photo-cell control unit C, responsive to thermalconditions of the welding operation, the heating eflect oi the flamewill be varied as necessary, to maintain substantially the same thermalcondition at all points of the welding operation and thereby produce auniform weld.

Photo-cell unit C comprises a photo-electric cell 80, disposed at thelower end of a tube 9| which protects the cell and also excludes thermalradiations other than those emanating rrom the underside of the weldingseam. Photo-cell is of a type responsive to variations in the radiationswhich reflect the thermal condition of the welding seam, and causesproportional variations in the electrical impulses passing through thephoto-cell and to an amplifier 92 through wires 93. In the amplifier 92,the impulse variations are amplified to provide more sensitive control,the amplifier being connected with a reactor 94 by wires 95. In thereactor, the variations in impulse are imposed upon electricity passingto solenoid S through wires 96, the reactor being supplied by wires 91from an A. C. supply line 98. Thus, in response to a decrease orincrease in the radiations reflecting the thermal condition of thewelding operation, the control unit 0 will cause the force exerted bysolenoid S on the control spring of the combined regulator andproportioner RP to increase or decrease, so that the heating efl'ect ofthe flames discharged from head H will increase or decrease, as the casemay be, to maintain substantially uniform welding conditions along theseam.

At the beginning of the welding operation, the combustible mixturepreferably consists of oxygen and acetylene, valves V being adjusted toprovide heating flames having the highest temperature and greatestheating effect. After the initial portion of the seam has been heated tothe desired temperature, and the welding operation thus started, therelative motion between the head H and control unit C and the workpieceW is begun, so that the heating flames will be applied to successiveportions of the seam. As the welding operation progresses, variations inthe temperature and thermal condition of the weld at the point ofapplication of the flames will be compensated for and corrected byvariations in the heating eflect of the flames.

Similarly, when a mixture of fuel gases rather than oxidizing gases isutilized, the combustible mixture at the beginning of the operationpreferably consists of acetylene and oxygen. After the welding operationis started, and welding along the seam progresses, reductions in theheat necessary to maintain the desired thermal condition will beeffected by the introduction of hydrogen into the fuel gas mixture and adecrease in the pressure and flow of acetylene and in the pressure andflow of oxygen, as controlled by solenoid S and the combined regulatorand proportioner RP, in turn controlled by photo-cell unit C.

From the foregoing, it will be apparent that this invention provides anefficacious and highly desirable method of and apparatus for controllingor varying characteristics of a heating flame. The method of thisinvention has advantages not possessed by other methods of changing theheating effect by varying the constituents of the combustible mixture.In the case of an oxy-acetylene flame, for instance, if the amount ofoxygen in the combustible mixture should be decreased without varyingother constituents, a neutral flame would become carburizing or anoxidizing flame would become neutral. Similarly, if the amount ofacetylene is reduced sufllciently to lower the temperature and heatingeifect of the flame, then a neutral flame would become oxidizing or acarburizing flame would become neutral. Furthermore, if the supply ofboth oxygen and acetylene were reduced simultaneously without any otherchange in the combustible mixture, not only would the length of theinner cone be changed, but also the danger of flashbacks would beincreased due to the jet velocity becoming less than the velocity offlame propagation. Flashbacks and resultant backfires sometimes resultin expensive work being damaged or ruined.

Furthermore, while oxy-acetylene heating flames, and acetylene andhydrogen fuel gases. have been given as specific examples in explainingthis invention, it will be understood that these are only representativeof many other types of heating flames and fuel gases to which thisinvention is applicable. Thus, the method of this invention includesregulatin predetermined characteristics of a heating flame whilemaintaining other predetermined characteristics substantially constant,the flame being produced by a combustible mixture of fuel and oxidizinggases and at least a portion of the oxidizing gas being substantiallypure oxygen. Broadly, the method comprises varying the pressure and flowof at least one of the constituent gases in accordance with the pressureand flow of another of the constituent gases to increase or decrease theheating effect of the flame, the regulation of the pressure and flow ofthe constituent gases bein such that an increase in the pressure andflow of substantially pure oxygen occurs substantially simultaneouslywith an increase in the pressure and flow of a fuel gas of which agreater amount tends to increase the heating effect of the flame.

It will also be understood that the method and apparatus of thisinvention are useful in heating operations other than strip welding, andheating operations combined with other operations. For

instance, the principles of this invention are applicable to thenormalizing or softening of a relatively hard surface layer along thekerf produced by an oxygen cutting let; the principles of this inventionare applicable to flame hardening. i. e., local heating followed by asuitable cooling or quenching step to harden the heated surface; theprinciples of this invention are applicable to preheating for welding,or both preheating and. heating during actual fusion; the principles ofthis invention are applicable to preheating for oxygen cutting; and theprinciples of this invention are applicable to many other operationsinvolving heating, which will readily suggest themselves to thoseskilled in the art.

An advantage of the present invention resides in the simplicity ofconstruction and ease of operation in being able to vary the heatingeflect of the blowpipe flame as desired without the mechanismsheretofore required for increasing the separation between the work andthe blowpipe, or changing the rate of relative travel between the workand blowpipe. This has been possible because applicant has retained thelength of the inner cone of the blowpipe flame substantially constant.

What is claimed is: g

1. Apparatus for regulating the heating effect of a flame produced bythe combustion of fuel gas, comprising means for mixing oxidizing gashaving a. relatively high oxygen content and a stream of oxidizing gashaving a relatively low oxygen content to form an initial mixture; meansfor varying the proportion of oxidizing sas having a relatively highoxygen content and varying the pressure of said oxidizing gas of highoxygen content; means in addition to the other means for throttling theflow of said initial mixture; means for simultaneously varying thepressure of fuel gas; means for throttling the flow of said fuel gas;and means for mixing said initial mixture gases with such fuel gas toform a combustible mixture, whereby the proportion of oxidizing gashaving a relatively high oxygen content may be increased, the pressureof oxidizing gases may be increased, and the pressure of fuel gas may beincreased simultaneously, to produce an increase in the heating effectof said flame.

2. Apparatus for regulating a heating flame produced by the combustionof a fuel gas, comprising means for mixing fuel gas and an oxidizing gasmixture to form a combustible mixture; means for controlling the flow offuel gas supplied to said mixing means in accordance with the pressureof oxidizing gas; walls forming a chamber for mixing oxidizing gashaving a relatively high oxygen content and a stream of oxidizing gashaving a relatively low oxygen content: one of the chamber walls havingan orifice through which said oxidizing gas having a high oxygen contentpasses into said chamber; and means for passing oxidizing gas mixturefrom said chamber to said means for mixing fuel gas and oxidizing gasmixture at reduced pressure.

3. Flame heating apparatus comprising a blowpipe for mixing fuel gas andoxidizing gas to provide a combustible mixture which will produce a hightemperature heating flame; oxidizing gas richness regulating meanshaving a chamber provided with walls within which air and oxygen areadapted to be mixed; a valve in said regulating means for controllingthe flow of fuel gas from a fuel gas inlet to a fuel gas outlet; a wallof said chamber having an orifice through which oxygen is conducted tosaid mixing chamber; said regulating means including diaphragm means forcontrolling said fuel gas valve and subject on one 'side to the outletpressure of fuel gas and on the other side to the pressure of oxygen onthe inlet side of said orifice; and conduit means connecting saidblow-pipe with said fuel gas outlet and with said mixing chamber; saidregulating means including means for controlling the pressure of oxygensupplied to said oriiice.

4. Apparatus as deflned in claim 3, in which said oxygen pressurecontrol means comprises a valve and a diaphragm controlling said valve,movement of said diaphragm being controlled by oxygen pressure exertedagainst one side of said diaphragm.

5. Apparatus as deflned in claim 3, wherein said diaphragm meanscomprises a pair of spaced diaphragms connected together to move inunison. one 01' said diaphragms being subiect on one side to fuel gaspressure and the other of said diaphragms being of larger eflective areaand subject on its opposite side to ongen pressure with the spacebetween said diaphragms being vented to the atmosphere.

6. In a flame heating apparatus, including a blowpipe for mixing fuelgas and oxidizing gas to provide a combustible mixture. a combinedoxidizing gas pressure regulator and oxygen richness proportioner havinga chamber in which air and oxygen are mixed; said regulator andproportioner having a fuel gas inlet passage. a fuel gas outlet passage.an oxygen inlet passage to said mixing chamber; a valve for controllingthe flow of fuel gas from the fuel gas inlet passage to the fuel gasoutlet passage; a valve controlling the flow of oxygen from the oxygeninlet passage to the mixing chamber; said mixing chamber having a, wallin which is an orifice leading from said oxygen inlet passage to saidmixing chamber: a connection between said mixing chamber and saidblowpipe; an air supply passage leading to said mixing chamber: andmeans for controlling said fuel gas valve and responsive to variationsin pressure in said oxygen inlet 7. In flame heating apparatus asdefined in claim 6, means for controlling said oxygen valve including adiaphragm subiect on one side to the pressure in said oxygen inletpassage and on the other side to the pressure in said mixing chamher.

8. In flame heating apparatus as defined in claim 8, wherein means forcontrolling said oxygen valve comprises a, diaphragm 'and an adjustablespring acting against one side of said dinphragm, said diaphragm forminga wall between said oxygen inlet passage and said air supply passage,and said orifice leading from said oxygen inlet passage to said mixingchamber through said diaphragm.

9. A method of regulating characteristics of a flame producedprincipally by the combustion of acetylene, which comprises mixingacetylene and hydrogen to form a fuel gas mixture; supplying ongen tosupport the combustion of such mixture; and increasing the proportion ofacetylene in said fuel gas mixture and simultaneously increasing thepressure and flow of oxygen, to produce an increase in the heatingeifect of said flame.

10. A method of regulating the heating eil'ect of a flame produced bythe combustion of a mixture of acetylene, hydrogen, and oxygen, suchmethod comprising varying the pressure and rate of flow effected by saidpressure 0! a 110W stream of acetylene; regulating the pressure and flowof a stream of oxygen directly in accordance with the varied pressure oiacetylene; simultaneously proportioning the flow of a stream of hydrogeninversely to and with the flow of acetylene; and mixing the acetylenewith the gierogen and with the owgen to form said mix- 11. A method ofproducing a flame having an adjustable heating eifect which comprisesproviding a supply of diluent gas at desired supply pressure; providingsupplies of combustible mixture forming gases comprising acetylene andoxygen -at least one of which is under higher pressure; reducing thepressure of said one of said combustible mixture forming gases andmaintaining such initially reduced pressure above said diluent supplypressure; further reducing the pressure of said one combustible mixtureforming gas to a value equal to said diluent supply pressure whileadmixing said one gas with said diluent which is inert with respect tothe said one gas to form an initial mixture having a desiredcomposition; regulating the pressure of the other oi said combustiblemixture forming gases in accordance with said initially reduced pressureof said one combustion mixture forming gas; and admixing said othercombustible mixture forming gas under the head of its regulated pressurewith said initial mixture to form. when ignited, said flame.

12. A. method of varying the heating eifect of a flame which comprisesproviding a supply oi diluent gas at desired supply pressure; providingsupplies of combustible mixture forming gases at least one of which isunder higher pressure: reducing the pressure of said one of saidcombustible mixture forming gases and maintaining such initially reducedpressure above said diluent supply pressure; further reducing thepressure of said one combustible mixture forming gas to a value equal tosaid diluent supply pressure while admixing said one gas with saiddiluent which is inert with respect to the said one gas to form aninitial mixture having desired adiustable proportions; regulating thepressure of the other of said combustible mixture forming gases inaccordance with said initially reduced pressure of said one gas; andflnally admixing said other combustible mixture forming gas under thehead of its regulated pressure with said initial mixture to form, whenignited, said flame.

13. A method of varying the heating effect of a flame which comprisessupplying air at a desired pressure; supplying oxygen at a higherpressure; reducing the pressure of said oxygen and maintaining suchinitially reduced pressure above the air supply pressure: furtherreducing the pressure of said oxygen to a value equal to said air supplypressure while admixing said oxygen with said air to form a mixtur ofair and oxygen having desired proportions; regulating the pressure of asupply of fuel gas in accordance with said initially reduced pressure ofoxygen alone; admixing proportioned amounts of said fuel gas under thehead of said regulated pressure with proportioned amounts of saidmixture of air and oxygen to form, when ignited, said flame; andadjusting the degree by which said initially reduced pressure or owgenexceeds the air supply pressure to vary the heating eifect or said flamewithout substantially changing the proportionality between oxygen andfuel in said flame.

A met f va yin the heating eflect of a flame which comprises providing asupply of diluent gas at a desired supply pressure; providing a supplyof acetylene at a higher pressure; automatically reducing the pressureof said acetylene and maintaining such initially reduced pressure abovethe diluent supply pressure; further reducing the pressure of saidacetylene to a value equal to said diluent supply pressure whileadmixing said acetylene and diluent to form an initial mixture ofacetylene and diluent of desired proportions; regulating the pressure oia supply of oxygen in accordance with said initially reduced pressure ofacetylene; mixing proportioned amounts of said oxygen under the head ofsaid regulated pressure with proportioned amounts of said initialmixture to form, when ignited, said flame; and adjusting the degree bywhich said initially reduced pressure of acetylene exceeds said diluentpressure to vary the heating effect of said flame without substantiallychanging the proportionality between oxygen and acetylene in the flame.

15. The method of adjusting the heating effect of a flame supplied by amixture of fuel gas and oxidizing gas which comprises flowing a diluentgas into one of the components of said mixture which is inert withrespect to the diluent, controlling the flow of the mixture component tobe diluted in response to a difference between the diluent pressure andthe pressurepf said one mixture component before being diluted and whenthe pressure of said one compo-l nent is above a predetermined value,controlling the flow of the other mixture component in response to thepressure difference between it and the pressure of the mixture componentto be diluted, and mixing said fuel gas with said 0111- dizing gas.

16. The method of adjusting the heating effect of a flame supplied by amixture of fuel gas and oxidizing gas which comprises flowing a diluentgas into one of the components of said mixture which is inert withrespect to the diluent, controlling the flow of the mixture component tobe diluted in response to the difference between the diluent pressureand the pressure of said one mixture component before being diluted andwhen the pressure of said one component is above a predetermined value,and mixing said fuel gas with said oxidizing gas.

17. The method of changing the velocity and heating effect of a gasflame supplied by a fuel gas, a gas rich in oxygen, and ages having arelatively low oxygen content which comprises initially adjusting theflow of the gas rich in oxygen, further controlling the flow of said gasrich in oxygen in response to the difference in pressure between italone and the gas having a relatively low oxygen content and adjustingthe flow of fuel gas in response to the pressure difference between itand said gas rich in oxygen to retain the length of the inner cone ofsaid flame constant and the ratio of oxygen to fuel constant for onekind of fuel.

18. An apparatus for changing the velocity and heat of a gas flamenozzle while maintaining the ratio of available oxygen to fuel gassubstantially constant which comprises, a line for supplying a gashaving a low oxygen content, a line for supplying a gas rich in oxygen,a line for supplying fuel gas, a valve in the line rich in oxygen, meansfor automatically adjusting said valve in response to pressuredifference between the line with relatively low oxygen content and theportion of the line rich in oxygen between the valve and the nozzle whensaid line rich in oxygen is above a given pressure, a valve in the fuelgas line, and means for automatically controlling said last mentionedvalve in response to the pressure diiference between the fuel gas lineand said portion of the line rich in oxygen between the nozzle and firstmentioned valve.

19. Apparatus for controlling the relative supply of a gas rich inoxygen content to a gas having a lower oxygen content, comprising a fuelsupply line, a supply line for each oxidizing gas, a valve in the linerich in oxygen, a device responsive to pressure difierence between saidline hav-- ing a low oxygen content and the portion of the line rich inoxygen adjacent but beyond the said valve when above a predeterminedpressure for controlling the supply of gas rich in oxygen, and

means beyond said valve for mixing the gas low in oxygen with the gasrich in oxygen prior to contact with the fuel and its supply line.

20. Apparatus for controlling the heat of a flame supplied by fuel andoxidizing gases and comprising a pair of passages for combustiblemixture forming gases, a third passage for a diluent gas, a valve in onepassage of said pair, a device for controlling said valve in response tothe pressure diil'erence between said one passage beyond said valve whenthe pressure is above a given amount and said third passage; means formixing the gas from said one passage and said diluent to form a gaseousmixture which is nonexplosive, a valve in the other passage of saidpair, a device for controlling said other valve in response to thedifference between the pressure in said other passage after its valveand the pressure in said one passage after its valve and before saidmixing means, and blowpipe means for mixing the gases from said otherpassage and the mixture from said mixing means.

21. The method of operating a blowpipe to change the heating effect ofthe flame without substantially changing the length of the inner cone ofthe flame which comprises supplyin two components of a fuel gas mixtureto said blowpipe, diluting one of said components with a compatiblediluent to form a non-explosive preliminary mixture, varying the flow ofsaid one component, further adjusting the flow of the varied componentin response to the pressure of the diluent gas flowing to the formationof said preliminary mixture, and adjusting the dew of the othercomponent in response to pressure of the adjusted first mentionedcomponent to maintain the ratio of oxygen to fuel gas substantiallyconstant.

' 22. The method of operating a blowpipe to change the heating effect orthe flame without substantially changing the length of the inner cone ofthe flame which comprises supplying two components of a fuel gas mixtureto said blowpipe, diluting one of said components with a compatiblediluent to form a non-explosive preliminary mixture, varying the flow ofsaid one component, further adjusting the flow of the varied componentin response to the pressure of the diluent gas flowing to the formationof said preliminary mixture, adjusting the flow of the other componentin response to pressure of the adjusted first mentioned component tomaintain the ratio of oxygen to fuel gas substantially constant, andreducing the pressure of the first mentioned component subsequent to itscontrol of said other or second mentioned component, said dilutingincluding mixing said diluent and first mentioned component after thepressure or the first component has been reduced.

23. The method of operating a blowpipe to change the heating efi'ect orthe fiame without substantially changing the length or the inner cone oithe flame, which. comprises supplying two unmixed components 01' a fuelgas mixture to said hlowpipe, flowing a diluent into one or saidcomponents which is non-explosive with the diluent, controlling the now01' said diluent in response to a reduced pressure or said one of saidcomponents, controlling the flowing 01' said one of the components withwhich the diliuent is mixed, and controlling the now of the othercomponent in response to the pressure 0! the flowing firstmentionedcomponent with which the diluent is mixed.

24. Apparatus for changing the heating eflect or the flame from ablowpipe which comprises means for supplying two components of a fuel gamixture to a blowpipe, means for supplying a diluent gas for one of saidcomponents, a manually adjusted valve for said one of said componentswhich valve is also automatically adjustable in response to pressure ofsaid diluent gas being supplied, a valve for controlling the fiow oi theother component in response to pressure of the first mentioned componentbeing supplied, a pressure reducing orifice through which the firstmentioned component passes after it so has controlled the supply of thesecond component, a mixing chamber with which said diluent 16 gas supplymeans is connected and into which said first component also passes alterbeing reduced in pressure by its passage through said orifice. and meansfor conducting the controlled mixture or diluent gas and first componentas well as the controlled second component to said blowpipe.

ElIBE W. DECK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 985,896 Hopkins Mar. 7, 19111,213,159 Dalen Jan. 23, 1917 1,325,116 Bebille Dec. 16, 1919 1,539,630Beaird May 26, 1925 2,089,014 Bucknam et al. Aug. 3, 1937 2,089,015Bucknam et ai Aug. 3, 1937 2,099,029 Jones Aug. 3, 1937 1,719,898 McNeilJuly 14, 1932 2,193,240 Schmidt Mar. 12, 1940 2,280,029 Crowe Apr. 14,1942 2,196,902 Jones Apr. 9, 1940 2,364,645 Mott Dec. 12, 1944 FOREIGNPATENTS Number Country Date 554,664 German July 14, 1932 825,890

British Feb. 20, 1930 Certificate of Correction Patent No. 2,416,161.

February 18, 1947.

EIBE W. DECK It is hereby certified that errors appear in the rintedspecification of the above numbered patent requiring correction asfollows: discs; column 10, line 64, claim 2, strike out the words olumn7, line 43, for dies read at reduced pressure and insert the same afterthe word chamber and before the semi-colon, line 61, same claim; andthat the said Letters Patent should be read with these correctionstherein that the same may co nform to the record of the case in thePatent Office.

Signed and sealed this 13th day of May, A. D. 1947.

LESLIE FRAZER,

First Assistant Commissioner of Patents.

mentioned component after the pressure or the first component has beenreduced.

23. The method of operating a blowpipe to change the heating efi'ect orthe fiame without substantially changing the length or the inner cone oithe flame, which. comprises supplying two unmixed components 01' a fuelgas mixture to said hlowpipe, flowing a diluent into one or saidcomponents which is non-explosive with the diluent, controlling the now01' said diluent in response to a reduced pressure or said one of saidcomponents, controlling the flowing 01' said one of the components withwhich the diliuent is mixed, and controlling the now of the othercomponent in response to the pressure 0! the flowing firstmentionedcomponent with which the diluent is mixed.

24. Apparatus for changing the heating eflect or the flame from ablowpipe which comprises means for supplying two components of a fuel gamixture to a blowpipe, means for supplying a diluent gas for one of saidcomponents, a manually adjusted valve for said one of said componentswhich valve is also automatically adjustable in response to pressure ofsaid diluent gas being supplied, a valve for controlling the fiow oi theother component in response to pressure of the first mentioned componentbeing supplied, a pressure reducing orifice through which the firstmentioned component passes after it so has controlled the supply of thesecond component, a mixing chamber with which said diluent 16 gas supplymeans is connected and into which said first component also passes alterbeing reduced in pressure by its passage through said orifice. and meansfor conducting the controlled mixture or diluent gas and first componentas well as the controlled second component to said blowpipe.

ElIBE W. DECK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 985,896 Hopkins Mar. 7, 19111,213,159 Dalen Jan. 23, 1917 1,325,116 Bebille Dec. 16, 1919 1,539,630Beaird May 26, 1925 2,089,014 Bucknam et al. Aug. 3, 1937 2,089,015Bucknam et ai Aug. 3, 1937 2,099,029 Jones Aug. 3, 1937 1,719,898 McNeilJuly 14, 1932 2,193,240 Schmidt Mar. 12, 1940 2,280,029 Crowe Apr. 14,1942 2,196,902 Jones Apr. 9, 1940 2,364,645 Mott Dec. 12, 1944 FOREIGNPATENTS Number Country Date 554,664 German July 14, 1932 825,890

British Feb. 20, 1930 Certificate of Correction Patent No. 2,416,161.

February 18, 1947.

EIBE W. DECK It is hereby certified that errors appear in the rintedspecification of the above numbered patent requiring correction asfollows: discs; column 10, line 64, claim 2, strike out the words olumn7, line 43, for dies read at reduced pressure and insert the same afterthe word chamber and before the semi-colon, line 61, same claim; andthat the said Letters Patent should be read with these correctionstherein that the same may co nform to the record of the case in thePatent Office.

Signed and sealed this 13th day of May, A. D. 1947.

LESLIE FRAZER,

First Assistant Commissioner of Patents.

